Refrigerating machine



June 12, 1928.

3,673,153 F. B. MacLAREN REFRIGERATIG MACHINE Filed June 15. 1922 4- f 4- 7 a a i 3 Y l vs V9 FIG l WGSLWW Patented June 12, 1928.

l 1,613,153 -UNITED srnxrasI` PATENT OFFICE,

FREDERICK B. MAOLAREN, OF JAMAICA, NEW YORK, ASVSIGNOR TO THE MAGLABEN ELECTRIC APPLIANCE CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

Application led June 15,

This inventionrelates to improvements in refrigerating machinery andI especially .to that type in which air is used as a refugerant.

One object of this invention is to provide a simple and comparatively inexpensive apparatus for the compressing and expanding of air; a further object 1s the provislon of a rotary compressor without valve gear; a still further object is the provision of a compound expander without valve gear. Other objects will appear from the follows ing description of the invention at the end of which the invention will be claimed.

Another important object of the invention is to provide mechanism intermediate the compressin and expanding units which will transfer uid from theJ compressor to the expander without a material dimunition of pressure. Still another object is thel provision of means for eliminating expansion volumetric capacity intermediate compresser and expander units, particularly as applied to refrigerating machinery?.

The invention is illustrated somewhat diagrammatically in the accompan ing drawings forming -part hereof and in w ich Figure is asectional elevation of the ma chine.

Fig. 2 is a detail showing the relative frame and field yoke, 2 is the motor armature, 3 the commutator, 5 the field poles and 4 the field coils. The armature 2 is supported by the bearings 6 and'7 and drives the gears 8, 9 and 10. Meshing with the gear 8 is a gear 11, which forms a compressor element. The gear 9 meshes with a gear 12 and forms the admission part of' the expander. The gear 10 meshes with the gear 13 and forms thevexpansion part of an air en e. The bearings 14, 15 and 16 Vsupport t e main shaft while the bearin S17,

18 and 19 support the auxiliary sha A casing 20 is formed over the gears and is REFRIGERATIN G MACHINE.

1922. Serial No. 568,417.

made up of six cylinders in which the gears revolve. Base plate 21 supports the motor, compressor and expander. The air inlet 22 delivers air to the gear-pump where it is compressed' and :forced out through the pipe 23 into the cooler or cooling coil 24. From this cooler the air is delivered by pipe 25 toslon is exhausted 'through thel pipe 27 and' J0 delivered Vto the point where refrigeration 1s required.

In action the motor drives the compressor element having the gears 8 and 11 taking air from the place to be cooled through the pipe 22. Ijhis air is carried by the gear teeth around the casing 2O and deliveredto the pipe 23. The gear teeth of the gears 8 and 11 should fit the casing 20 tightly except close to the point of meshing. The compressed air passes through the cooler 24 where its temperature is dropped to a few degrees above that of the surrounding at-y mosphere and it is then led to the inlet side of the admision element of the expander formed by the gears. 9 and 12.' This element acts as a cut-0H for the air a certain fixed amount of air being'delivered at each revolution to the expander element formed by the gears 10 and 13. The volume of the space left between the gear teeth and -the casing lin lthe expander ele- 'I ment is much larger than in the admission element, therefore, the air expands doing work against the gear teeth and thus pro- .Mducin a drop in temperature. It isdesirable t at the length of the -port 26 be quite short for eiicient operation. I have found that the relative volumes of the three elements, compressor, admitter and expander may well have substantially the ratio of 8--1-4 respectively.

The reason for eliminating as far as pos' sible any length to the port 26 is to prevent i' expansion of the refri erating fluid rior to 4entry into the-expan er ear for i expan.

sion-occurred'in the pipe tength between the compressor and expander, no refrigeration would occur. It is for this reason that the gears 13 and 10 are placed at anA angle relative to the admission gears, this position permitting the shortest path between the admission unit and the expander and permitting entrance of the compressed `iuid into the expander at the proper' intervall when the gears of the expander and admission element are separated. The compressed fiuid is thus enabled to expand while doing work andv consequently brings about a pronounced drop in temperature. fThe admission element carries a unitary charge of fluid under uniform pressure from the pipe line 25 into the expander and prevents a sudden drop of pressure which would occur if no mechanism in the natureof a valve were interposed between thescompressor-Jand expander.

' It will be obvious to those skilled in the art to which the invention relates that modifications may be made in details of construction and arrangement without departing from the spirit of the invention and within the scope of the appended claims.

I claim: `1. A refrigerating machine comprising the combination of a gear-pump compressor,

a gear-pump admission elementoperative as a cut-olf for the compressor and having the centers of its gears in alignment with vthe centers vof the gears of the compressor, a gear-pump expander having the center of one of its gears displaced in respect to the center of one of the gears of the admission element to accommodate a short port provided in thevpump-casing from the admission element to the expander, the gear-pumps,

. ceeding the and the volume of the expander, and the ume of the admission element.

Vto

a motor for a cooling coilconnected to the outlet of the compressor and to the inlet of the admission element, and an air intake for the compressor and an air voutlet for the expander, the volume of the compressor exvolume of the admission element volumeof the expander exceeding the vol- 2. In a refrigerating machine, the combination ofa compressor unit adapted to compressY refrigerating: fluid, an expander unit,

and an admission unit, each of said units being formed of interengaged gears,- means intermediate the compressor and the admission unitfor coolin said fluid, and a port intermediatethe a mission unit and expander unit, the volumetric capacity o-f the port relative to that of the expander being small.

3. In refrigerating apparatus, the combination of a gear pump compressor adapted to compress a refrigerating fluid, a cooling means for said fluid connected to the compressor, a gear admission valve, a gear pump expander, a gear of` said compressor an valve being positioned on a common shaft and another gear of said compressor and valve being positioned on a common shaft, and a gear expander adjacent the valve, one of the gears of said expander being mounted on a shaft in extension of one of said common shafts for the compressor and valve, and another of the gears of the expander being mounted with thel shaft thereof displaced transversely from the plane of said common shafts, connections intermediate the compressor valve and expander, the length of the connection intermediate the expander in the valve bein less than that of the connection between t e compressor and valve, the volumetric ratio between the compressor, expander and valve being in decreasing magnitude, and means for operating said compressor. A

4. In refrigerating apparatus, the combination of a `power source, a gear pump compressor operatively connected to said power source comprising two adjacent shafts, a gear mounted on each shaft and meshing one within the other, and an enclosin casing, a gear pump admission valve adjacent the compressor having'two gears mounted upon the extensions of the shafts of said compressor. and an enclosing casing, a gear pump expander adjacent the valve and having two gears in mesh with each other, and an enclosing casing, one of said expander gears being mounted on an extension of one kof the common shafts of the compressor and FREDERICK B. MAOLAREN. 

